Improvement in registering steam-gauges



THOMAS C. HARGRAVE.

Impmv-ement nRe-gistering Steam Gauges.

Patented March 19, 1872.`

Nov. 124,816.

link a and rack b.

THOMAS O. HARGRAVE, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT lN REGISTERING STEAM-GAUGES.

Specification forming part of Letters Patent No. 124,816, dated March 19, 1872.

To all whom it may concern.-

Be it known that I, THOMAS C. HARGRAVE,

of the city of Boston and State of Massachtt.A

setts, have invented certain Improvements in Registering Steam-Gauges; and I hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawing making a part of this specification, in Which- Figure 1 represents a front elevation of the gauge with the dial removed. Fig. 2 represents a side elevation of a portion of the mechanism. Eig. 3 represents a plan and elevation of the adjustin g device. Fig. 4 represents the main indicating-hand. Fig. 5 represents the maximum hand, and Fig. 6 represents a gaugecock with a locking device.

rlhe object of my invention is to provide a steam-gauge to indicate and register the negligence of an engineer in allowing the steam pressure in a boiler to exceed a determined pressure; and consists in a bar, provided with `a star-wheel and screw revolving on the same center with the main hand, and actuating a registering-hand attached to a pinion.

In the said drawing, Ais the ordinary gau gespring, working the pinion b by means of the On the frame B rises a pillar, c, which has a groove, c, around it near its top to receive the clasp-spring of the maximum hand 7c, and is hollow for the spindle a to pass through and carry the main hand of the gauge z on its end. D is a bar, 4made as shown in Fig. 3, and has on it standards d d, which serve as bearings for a shaft, e, and has also the spring-clasp df, which slips over and attaches the bar to the pillar o. The shaft e has at one end a star-wheel, g, and Vat the other a screw, f. The indicating-hand E, Fig. 5, is attached to a pinion and collar, i, and is bent at t', as shown, for the purpose of allowing the main hand with its spring h topass clear of it. The collar and pinion t' are fitted over the pillar c, and the teeth of the pinion engage in the worm of the screw j'. Above the collar t in the groove c', by means of a spring-clasp or otherwise, is attached the maximum handle, and above this is placed the main hand of the gauge z on the head of the spindle af, which slightly protrudes above the pillar c. This main hand z, Figa, is made with a bent spring, h, near its end. A bent spring, o, soldered to the bar D, presses lightly against the shaft e to act as a slight brake lon it and steady its revolutions. The handle to the steam-cock. Fig. 6, is made bent, as

shown at P, one arm, x, when the steam is turned on, being vertical to the face of the gauge, and fitting into a depression (not shown) in the rim of the face, the other arm, y, being parallel to the steam-pipe, and having through its end two openings, I and N, transverse'to each other. In the gauge-pipe is a shallow screw-hole, N, corresponding to the hole 011 the back side of the opening P. NVhen the steam is turned on, the gauge-face screwed down, and both are to be locked, the handle P is brought into the position shown in Fig. 6, a screw is screwed into the hole N till its head is iush with the face of the opening P', and a hasp of a padlock introduced into the said openin g, the padlock locked, and the head of the screw N is protected, so it cannot be withdrawn, and the gauge opened, or the steamcock turned off.

The operation of my gauge is as follows: The steam being turned on, the main hand passes around the dial until the spring h comes in contact with a tooth of the starwheel, which it pushes before it as it passes. This movement of the star-wheel turns the shaft e and screw f, which turns the pinion z' and moves the indicating-hand one space. This operation is repeated each time the main hand passes above any given point at which the star-wheel has been set. The max hand 7c is carried around the dial to the highest point attained by the main hand by means of the spring 'h engaging it, and yis there left, showing the highest pressure reached.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. The radially-adjustable bar I) with the shaft e, having a star-wheel and worm-gear, in combination with the registering-hand E, as set forth, and for the purpose described.

2. In a registering pressure gauge, the steam-spring A, rack b, pinion b', spring M, frame B with its pillar c and spindle a and main hand e, in combination with the adjustable bar D and indicating-hand E, substantially as and for the purpose set forth.

. THOMAS O. HARGRAVE.

Witnesses:

J. Il. M. GILLEY,

DANIEL PRATT. 

